docs: def _get_raw_key(self, key_id):
          """Retrieves a static, randomly generated, RSA key for the specified key id.
  
          :param str key_id: User-defined ID for the static key
          :returns: Wrapping key that contains the specified static key
          :rtype: :class:`aws_encryption_sdk.internal.crypto.WrappingKey`
          """
          try:
              static_key = self._static_keys[key_id]
          except KeyError:
              private_key = rsa.generate_private_key(public_exponent=65537, key_size=4096, backend=default_backend())
              static_key = private_key.private_bytes(
                  encoding=serialization.Encoding.PEM,
                  format=serialization.PrivateFormat.PKCS8,
                  encryption_algorithm=serialization.NoEncryption(),
              )
              self._static_keys[key_id] = static_key
          return WrappingKey(
              wrapping_algorithm=WrappingAlgorithm.RSA_OAEP_SHA1_MGF1,
              wrapping_key=static_key,
              wrapping_key_type=EncryptionKeyType.PRIVATE,
          )